APES, Chapter 9

age structure

Percentage of the population (or number of people of each sex) at each age level in a population.

birth rate

Annual number of live births per 1,000 people in the population of a geographic area at the midpoint of a given year.

death rate

Annual number of deaths per 1,000 people in the population of a geographic area at the midpoint of a given year.

demographic transition

Hypothesis that countries, as they become industrialized, have declines in death rates followed by declines in birth rates.

emigration

Movement of people out of a specific geographic area.

family planning

Providing information, clinical services, and contraceptives to help people choose the number and spacing of children they want to have.

fertility

The number of births that occur to an individual woman or in a population.

immigration

Migration of people into a country or area to take up permanent residence.

infant mortality rate

Number of babies out of every 1,000 born each year that die before their first birthday.

life expectancy

Average number of years a newborn infant can be expected to live.

migration

Movement of people into and out of a specific geographic area. See immigration, emigration.

population change

An increase or decrease in the size of a population. It is equal to (Births + Immigration) - (Deaths + Emigration).

replacement-level fertility

Number of children a couple must have to replace them. The average for a country or the world usually is slightly higher than 2 children per couple (2.1 in the United States and 2.5 in some developing countries) because some children die before reaching their reproductive years.

total fertility rate (TFR)

Estimate of the average number of children who will be born alive to a woman during her lifetime if she passes through all her childbearing years (ages 15-44) conforming to age-specific fertility rates of a given year. In simpler terms, it is an estimate of the average number of children a woman will have during her childbearing years.